“…However, limitations existed in these studies. The overall relationship is not well understood because these results were confined to a few industrial sectors (Amjad-Sardrudi et al, 2012; Barreto, Swerdlow, Smith, & Higgins, 1997; Cantley et al, 2015; Cohen, 1973b; Lees et al, 1980; Moll van Charante & Mulder, 1990; Picard, Girard, Simard, et al, 2008; Sbihi, Davies, & Demers, 2008), relied on worker’s opinion or recall (Clausen et al, 2009; d’Errico & Costa, 2012; Dias & Cordeiro, 2007, 2008; Melamed, Luz, & Green, 1992), or were not adjusted for age or experience (Barreto et al, 1997; Dias & Cordeiro, 2008; Melamed et al, 1992; Moll van Charante & Mulder, 1990) or occupation or safety hazard (Amjad-Sardrudi et al, 2012; Girard et al, 2009; Kling et al, 2012; Lees et al, 1980; Melamed et al, 1992; Moll van Charante & Mulder, 1990; Picard, Girard, Courteau, et al, 2008; Picard, Girard, Simard, et al, 2008; Sbihi et al, 2008; Yoon et al, 2015). …”